Guys, i recently moved overseas, and where my f5 has been built and biased on 230vac, my new home has 220v (at least according to spec, haven't measured actual yet as my stuff is still on its way on a container vessel).

Given the psu is unregulated, what can i expect when i turn the amp on?

Look at the picture attached. The purple lines indicate the 0V star point. It is very important. connect both supply 0V points to the star point. From the star point all 0V connections run to individual channels. From the star point run wires to RCA inputs 0V (RCA's are isolated from chassis). keep wire lengths for left and right channels equal length. The only ground (earth) connection is indicated by blue. The mains earth is connected to the chassis there. On the power supply I have a 10ohm connecting chassis earth to the 0V point.

Guys, i recently moved overseas, and where my f5 has been built and biased on 230vac, my new home has 220v (at least according to spec, haven't measured actual yet as my stuff is still on its way on a container vessel).

Given the psu is unregulated, what can i expect when i turn the amp on?

Just less overhead. And by the way, the transformer will be cooler (less saturation). The bias will remain (almost) the same. But you will normally never hit the power rail, and the F5 intrinsically has soft-clipping anyway.